function h=UT(x,ylow,yupper,c);
% Hyun-Han Kwon(2006.4)
% .9*[1 1 1]

% setting all the arguments as columns
x=x(:); ylow=ylow(:); yupper=yupper(:);
[m1,n1]=size(x);[m3,n3]=size(ylow);
[m4,n4]=size(yupper);
%if nargin==4,c='y';end;
if nargin <4,error('At least 4 arguments needed');end;
if n1~=1|n3~=1|n4 ~= 1 
   error('Arguments must be vectors [m,1]');
elseif m1~=m3|m1~=m4|m3~=m4
   error('Arguments must be the same length');
end
x1=[x; flipud(x); x(1)];
y1=[yupper; flipud(ylow); yupper(1)];
h=fill(x1,y1,c);
set(h,'edgecolor',0.75*[1 1 1]);
